Gummiboot: Switch to zip archive.

For some reason tarballs from cgit have a different hash each time you download.
Merge commit 'refs/top-bases/experimental/overlays' into experimental/overlays

# By Shea Levy
# Via Shea Levy
* commit 'refs/top-bases/experimental/overlays':
  Gummiboot: Switch to zip archive.
Merge branch 'master' into refs/top-bases/experimental/ruby

# By Shea Levy
# Via Shea Levy
* master:
  Gummiboot: Switch to zip archive.
Merge branch 'experimental/overlays' into refs/top-bases/experimental/ruby

* experimental/overlays:
Merge commit 'refs/top-bases/experimental/ruby' into experimental/ruby

# By Shea Levy
# Via Marc Weber (3) and Shea Levy (1)
* commit 'refs/top-bases/experimental/ruby':
  Gummiboot: Switch to zip archive.